1. Field of the Invention
The present invention relates to an inductive proximity switch, formed as a high-frequency generator, where the oscillator coil exhibits a core which is saturation-sensitive relative to a magnetic field to be determined.
2. Brief Description of the Background of the Invention Including Prior Art
A proximity switch is known from the German Patent Application Laid Open No. DE-OS 32 44 507. According to this reference, the core of an oscillator coil is made of ferrite and is closed by a corresponding yoke body. Consequently, based on an approach of a magnetic field or, respectively, by an intensification of a magnetic field, only a damping of the swinging oscillator can be achieved. A decrease of the oscillator current coincides with an increase in damping and, on the other hand, in opposite direction, removal of the damping is associated with an increase of the oscillator current. It is a requirement of the evaluation circuit that the changes of the oscillator current occurring in two directions are transformed by a switching circuit.
This proximity switch is associated in practical applications with the disadvantage of either not being sufficiently sensitive or that it cannot be produced in a sufficiently small size. In addition, an excess expenditure of switching techniques is required in order to transform the decrease of the oscillator current caused by the approach into an active switching command.